A solid catalyst that includes a transition metal catalyst component (e.g., titanium compound) and a main group metal catalyst component (e.g., aluminum compound) has been widely known as an olefin polymerization catalyst.
An olefin polymerization catalyst that utilizes a magnesium compound as a support exhibits remarkably improved polymerization activity. A polymer that exhibits high stereoregularity can be produced from an α-olefin having 3 or more carbon atoms by adding an electron donor compound such as an ester compound to the catalyst.
For example, a technique that treats a solid titanium catalyst component that supports an electron donor compound (e.g., phthalic acid ester) with a vinyl group-containing silicon compound (Patent Literature 1 (JP-A-3-234707)) is known.
However, di-n-butyl phthalate and benzylbutyl phthalate (i.e., phthalic acid ester) are designated as substances of very high concern (SVHC) specified by Registration, Evaluation, Authorization and Restriction of Chemicals (REACH), and a catalyst system that is not so designated has been desired from the viewpoint of a reduction in environmental load.